On Fri, Apr 20, 2012 at 10:15 PM, Peter Bergner <berg...@vnet.ibm.com> wrote:
> We're still hitting the overzealous assert identified in PR49246 that is
> looking for empty LTO partitions, even after the change to a checking assert.
> How about we backport Honza's mainline patch that stops the creation of empty
> partitions in the first place? Speaking with honza on IRC, he thought it was
> probably a good idea to backport it.
>
> I bootstrapped and regtested the backport patch below on powerpc64-linux with
> no regressions.
>
> Ok for the 4.6 branch?
Ok.
Thanks,
Richard.
> Peter
>
>
> Backport from mainline
> 2011-06-11 Jan Hubicka <j...@suse.cz>
>
> PR lto/48246
> * lto.c (lto_1_to_1_map): Don't create empty partitions.
> (lto_balanced_map): Likewise.
>
> Index: gcc/lto/lto.c
> ===================================================================
> --- gcc/lto/lto.c (revision 186600)
> +++ gcc/lto/lto.c (working copy)
> @@ -893,7 +893,8 @@ lto_1_to_1_map (void)
>
> for (node = cgraph_nodes; node; node = node->next)
> {
> - if (!partition_cgraph_node_p (node))
> + if (!partition_cgraph_node_p (node)
> + || node->aux)
> continue;
>
> file_data = node->local.lto_file_data;
> @@ -923,13 +924,13 @@ lto_1_to_1_map (void)
> npartitions++;
> }
>
> - if (!node->aux)
> - add_cgraph_node_to_partition (partition, node);
> + add_cgraph_node_to_partition (partition, node);
> }
>
> for (vnode = varpool_nodes; vnode; vnode = vnode->next)
> {
> - if (!partition_varpool_node_p (vnode))
> + if (!partition_varpool_node_p (vnode)
> + || vnode->aux)
> continue;
> file_data = vnode->lto_file_data;
> slot = pointer_map_contains (pmap, file_data);
> @@ -943,8 +944,7 @@ lto_1_to_1_map (void)
> npartitions++;
> }
>
> - if (!vnode->aux)
> - add_varpool_node_to_partition (partition, vnode);
> + add_varpool_node_to_partition (partition, vnode);
> }
> for (node = cgraph_nodes; node; node = node->next)
> node->aux = NULL;
> @@ -1050,8 +1050,9 @@ lto_balanced_map (void)
>
> for (i = 0; i < n_nodes; i++)
> {
> - if (!order[i]->aux)
> - add_cgraph_node_to_partition (partition, order[i]);
> + if (order[i]->aux)
> + continue;
> + add_cgraph_node_to_partition (partition, order[i]);
> total_size -= order[i]->global.size;
>
> /* Once we added a new node to the partition, we also want to add
> @@ -1231,6 +1232,8 @@ lto_balanced_map (void)
> }
> i = best_i;
> /* When we are finished, avoid creating empty partition. */
> + while (i < n_nodes - 1 && order[i + 1]->aux)
> + i++;
> if (i == n_nodes - 1)
> break;
> partition = new_partition ("");
>
>
